Mining machine

ABSTRACT

A continuous mining machine particularly adapted for low overhead coal seams having a relatively small diameter cutterhead of the non-oscillating or fixed head type driven by chains that also cut coal and convey it rearwardly to a gathering head mounted on the front of the machine. The gathering head carries a pair of counter-rotating discs having vanes cooperating with conveyor fences for sweeping and discharging coal to a conventional conveyor mounted on the machine chassis.

I United States Patent 1 [111 3,874,735

Delli-Gatti, Jr. [45 A 1, 1975 MINING MACHlNE 3.318.638 5/1967 Kilbournc 299/80 I 3.599.506 8/1971 Frccse 74/2421 FP [75] lnvemor- Frank Amlty- 3.730.593 5/1973 Karlovsky 299/80 Assignee: Lee Norse, Company, ChaI L [22] Filed: 1973 Primary Examiner-Ernest R. Purser [21] App]. NQ,; 403,379 Attorney, Agent, or Firm-Robert R. Paquin Related US. Application Data [62] Division of Scr. No. 243.973 April 14. 1972 Pat. [57] ABSTRACT NO. 1817579 A continuous mining machine particularly adapted for low overhead coal seams having a relatively small di- [52] U5. Cl 299/68, 299/80. 299/87 emeter cutterhead 0f the n cil ating or fix d head [51] Int. Cl. E2lc 27/24 yp driven y ha hat a s ut al and nvey it [58] Field of Search 299/6468, rearwardly to ga g a unt n th front 299/71 72, 75 76, 89, 78 80; 74/2423 of the machine. The gathering head carries a pair of 2411 FP counter-rotating discs having vanes cooperating with conveyor fences for sweeping and discharging coal to [56] Ref ren e Cit d a conventional conveyor mounted on the machine UNITED STATES PATENTS Chassls' 3,0625l8 1 H1962 Osgood 299/75 X 2 Claims, 6 Drawing Figures 3.874J35 SHEET 1 0f 3 mgrmum 1 ms N wot w MINING MACHINE This is a division of application Ser. No. 243,973, filed Apr. 14, 1972, and now US. Pat. No. 3,817,579.

BACKGROUND OF INVENTION This invention relates generally to the arts of mining and conveying materials and more specifically to continuous mining machines and improvements therein for mining coal and the like.

It is well known to provide continuous mining machines with a single cutter head rotating on a horizontal axis having a length greater than the width of the mining machine. The cutter head moves vertically up and down the face of a mine to mine coal, normally beginning at the top of the face and moving progressively down to the bottom and then returning to the top of the face where the machine moves forward to sump the head into the face to begin another downward sweep. Generally speaking, the trade calls this type of machine a fixed head miner.

Heretofore, fixed head miners have generally used high pressure hydraulic systems for moving the extendible ends of the cutter head inward and outward. Such use of hydraulic fluids under relatively high pressures seems to cause leakage problems that are difficult and expensive to solve. In addition, fixed head miners generally have their cutter heads connected to a driving transmission including gears and shafts extending directly to the cutter head. This type of transmission is expensive, makes the cutter head more bulky, and requires it to be of a relatively large diameter. Thus it is difficult to use this type of transmission arrangement in a mining machine having a cutter head with a relatively small diameter.

It is known to provide gathering heads for conveyors, such as used in continuous mining machines, with counter-rotating tables or discs mounted on the deck or apron of the gathering head and to provide each rotating disc with upstanding radially extending vanes to sweep material onto a conveyor located between the counter-rotating discs. However, it has been found that arranging the vanes to extend radially reduces the ability of the vanes to sufficiently sweep conveyed material onto the conveyor.

SUMMARY OF THE INVENTION The principal object of this invention is to substantially overcome or minimize the foregoing problems and to provide an improved continuous mining machine of the fixed heat type.

Other important objects include the following: to provide a novel driving system for the cutter head of a lixed head miner; to provide a cutter head driving system using a chain that transmits driving torque to the cutter head. cuts coal and acts as a conveyor; to P vide a miner cutter head driving system having a driving cutter chain with a lower run that remains tight durng operation, thereby serving also as a conveyor to carry coal rearwardly from the cutter head; to provide a novel means for mounting a transmission driving a chain-driven cutter head and for adjusting the chain; to provide a driving system enabling a cutter head to have a relatively small diameter; and to provide novel improvements in continuous mining machines useful for coal seams of thirty inches and less in height.

In general, the foregoing objects may be attained in a mining machine having a fixed cutter head of relatively small diameter and containing telescopically sliding end portions, each being moved inward and outward by a motor powered by relatively low pressure fluid and driving a thread means connected to each end portion. The cutter head is driven by a chain located centrally of the length of the cutter head from a transmission adjustably mounted on the boom to properly tension the chain. Novel means including a grease gunactuated jack is provided for adjusting the transmission and applying tension to the chain. The lower run of the chain is under tension during operation, thereby making it more effective as a conveyor to carry coal rearwardly from the cutter head.

One of the very important combinations of the invention is the concept of arranging the cutter head to cut coal and to convey it inwardly of its length to the central area of the cutter head where it is picked up and conveyed rearwardly to the gathering head by the lower run of the drive chain. Thus the drive chain serves three purposes: to drive the cutter head, to cut coal and to carry the cut coal rearwardly from the cutter head to the gathering head.

' BRIEF DESCRIPTION OF DRAWINGS The invention is described in connection with the accompanying drawings wherein:

FIG. I is a plan view of a mining machine embodying the invention;

FIG. 2 is a side elevational view of FIG. 1;

FIG. 3 is a fragmentary axial section of the front por tion of the miner showing a part of the cutter head and the details of the driving means for the cutter head;

FIG. 4" is a fragmentary section taken on line 4-4 in FIG. 3;

FIG. 5 is a fragmentary plan view of the gathering head; and

FIG. 6 is a view similar to FIG. 5 on a smaller scale of an alternate embodiment of the gathering head.

DESCRIPTION OF PREFERRED EMBODIMENT Looking at FIGS. 1 and 2, the mining machine 1 conventionally comprises a chassis 2 supported on a pair of crawler tracks 3 and carrying a conveyor 4 running from the front of the chassis 2 to beyond the rear on a tail-piece 5 having an articulated joint 6. A gathering head 7 is pivoted on the front of the chassis 2 and extends forwardly therefrom for conveying coal to the forward end of the conveyor 4. The conveyor 4 includes a-trough having the usual side flanges 8 and a chain 9 with cross bars 10 for carrying material along the conveyor trough. A boom 11 is pivotally mounted on the front end of the chassis 2 at 12, to extend upwardly and forwardly therefrom and is raised up and down by a pair of hydraulic cylinders 13 mounted between the chassis 2 and an intermediate portion of the boom 11. A cutter head 14 is rotatively mounted on the forward end of the boom 11. Motors 15 are mounted on the sides of the chassis 2 and are connected to transmissions 16 mounted on the outer sides of the boom 11 by shafts 17 having a universal joint 18 at each end and splined telescopic joints 19 between the ends. The cutter head 14 has the usual cutting bits 20 mounted on the ends of auger-shaped, helically extending flanges 21 arranged to urge coal broken away from a face by the bits 20 to move toward the center of the cutter head 14. It is believed that all of the foregoing structure is conventional in continuous mining machines.

Looking at FIGS. 1 and 3, the boom 11 is composed of a pair of horizontally spaced longitudinal side members 22 interconnected by a pair of longitudinallyspaced cross members to form an openwork construction seen when looking down on the boom 11. The cross members include a rear cross member 23 located intermediate the ends of the side members 22 and a front cross member 24. A pair of integral, horizontallyspaced arms 25 extend forwardly from the front cross member 24 and contain bearings 26, shown in FIG. 3, supporting the shaft 27 of the cutter head 14. The cutter head 14 comprises a central drum 28, a pair of outer drums 29 and a pair of extendible end portions 30 telescoped within the outer drums 29. The central drum 28 and the outer drums 29 engage splines on the shaft 27 as shown in FIG. 3 to rotate together in unison. Each extendible end portion 30 includes an inner sleeve 31 telescoping in the interior of the outer drums 29 and keyed therein by a key 32, thus anchoring the end portion 30 to rotate with the outer drum 29 while being able to telescope relative thereto.

The means for moving each end portion 30 relative to its outer drum 29 includes a hydraulic motor 34 mounted in the outer drum and driven by relatively low pressure fluid flowing through supply and return passages 33 extending through the boom arm 25 and the shaft 27. The motor 34 drives a long nut 35 threaded on a cooperating screw 36 fixed to the end portion 30. Both the nut 35 and the screw 36 are connected to their respective members by a universal joint 37 that allows the nut and screw to seek their own alignment with each other. The inner end of the nut 35 rotates in bearings 38.

It has been found that the use of the relatively low pressure hydraulic fluid motor 34 in conjunction with the screw 36 and cooperating nut 35 is capable of applying relatively large forces to move the end portion 30 inwardly and outwardly relative to the outer drum 29, thus eliminating the need for pistons and cylinders requiring relatively high fluid pressures to create the necessary forces required for telescoping the end portion 30. The use of the screw 36 and nut 35 provides a self-locking system since the screw is designed so that it cannot be caused to travel in the nut 35 by thrust forces acting on the end portion 30.

The central drum 28 includes a sprocket 40 at each end, and the inner end of each outer drum 29 carries a sprocket 41. Thus the sprockets 40 and 41 are located on the opposite sides or faces of the arms 25, as shown in FIG. 3. The sprockets 40 and 41 are driven by wide multiple-strand chains 42 from the transmissions 16 mounted on the sides 22 of the boom 11. Each transmission 16 includes a case 44 containing an output shaft 45 driving a sprocket 46 engaging a chain 42.

The multiple-strand chain 42 is formed of a series of links 48 pivoted together by pins 49 having heads 50 projecting beyond the sides of the chain. The chain 42 shown in FIG. 3 contains five strands, thus being relashown in FIG. 2, the same direction of rotation as the cutter head 14, thus cutting the coal downwardly and rearwardly from the cutter head 14. Due to being driven in a clockwise direction as shown in FIG. 2, the lower run or flight 43 of the chain 42 is tensioned which increases its effectiveness to carry the cut coal rearwardly to the gathering head 7. The tension on the lower run 43 makes the bits 51 on the chain 42 stand rigidly relative to the chain to make them more effective in carrying the coal rearwardly then they would be if the lower run 43 of the chain was slack.

Novel means is shown for adjusting the transmissions 16 relative to the boom side walls 22 to adjust the tension on the chains 42. Each transmission case 44 is longitudinally adjustable on key ways 52 formed in the side wall 22, and is attached to the side wall 22 by bolts 53 extending through slots in the transmission case 44 and threaded into the boom side walls 22. The forward end of the transmission case 44 includes a cylinder 55 containing a piston 56 projecting forward to engage an outwardly extending wing 57 on the boom 11. Thus the cylinder 55 is located between the transmission 16 and the outwardly extending wing 57 of the boom 11. The cylinder 55 contains a grease fitting 58 connected to a passage for feeding grease under pressure into the cylinder to urge the piston 56 forwardly against the boom wing 57, and thus to force the transmission case 44 rearwardly to increase the tension on the cutter chain 42.

When the proper chain tension is achieved, the sleeve nut 59 threaded on the forward portion of the cylinder 55 is screwed outwardly until engaged solidly against the boom wing 57 and a lock nut 60 is moved to lock the sleeve nut 59 in adjusted position. It will be noted that this arrangement provides a simple means for adjusting the transmission case 44. Once the chain tension is properly adjusted, the bolts 53 are tightened to lock the transmission case 44 in place solidly on the boom side wall 22.

The gathering head 7 is shown in FIG. 5 and includes a large apron or deck 65 having a forward end 66 and is pivoted at its rear end to the chassis 2 of the miner 1 in a conventional manner. A pair of counter-rotating discs 67 are mounted in the gathering head deck 65 and rotate in the direction of the arrows to move conveyed material centrally and rearwardly to the forward end 68 of the conveyor 4. The conveyor 4 includes the parallel side flanges 8 which extend forwardly into a pair of fences 69 flaring outwardly and terminating at or near the axis of each disc 67. The fences 69 are arranged to guide or cam material off of each gathering head disc 67 as they rotate beneath the fences. At the same time, the movement of the disc 67 urges the coal or other conveyed material rearwardly onto the front end of the conveyor 68.

A novel invention of this arrangement is the idea of providing upstanding vanes 71 on each disc 67 and extending the vanes 71 relative to the radius of the disc so the vanes 71 curve outwardly and rearwardly relative to the rotating direction of each disc, whereby, as they approach the periphery of each disc, they extend at a substantial angle relative to the radius and rearwardly relative to the direction of rotation of the disc. This manner of extending each vane 71 is preferred as it serves to aid in guiding the conveyed material off of the disc as each vane 71 passes beneath a fence 69. It can be seen that if the vane 71 extended radially, the

material might be caught between the vane 71 and the fence 69 to cuase damage to either member. It is preferable to curve each vane 71 relative to the curve of the fence 69 so that each portion of the vane 71 extends generally at a right angle relative to the fence 69 as it passes beneath it.

In an example of a gathering head contructed by the inventor, the surface of the discs 67 lie in the plane of the deck surface and the vanes 71 project above the deck surface about /8 inches.

The foregoing type of gathering head is particularly useful in a continuous miner designed for very low seams, i.e., seams of less than 30 inches in height.

The discs 67 are driven by a-drive system shown in dotted lines in FIG. 5, including a shaft 72 driven at each end by a motor 73 and driving gears 74 connected to a worm 75 engaging a worm gear 76 fixed to each disc 67. In addition, the shaft 72 simultaneously carries a sprocket driving the conveyor chain 9.

Another embodiment of gathering head 80 is shown in FIG' 6 employing oval or elliptical discs 81 arranged to rotate 90 degrees out of phase with each other and carrying vanes 82 similar to the vanes 71. This arrangement will oscillate the central area between the discs 81 back and forth and is believed to benefit the feeding of material onto the conveyor.

While several embodiments of the invention have been shown and described in detail, this invention is not limited simply to the specifically described embodiments, but contemplate other embodiments and variations utilizing the concepts and teachings of this invention.

I claim: 7

l. A mining machine comprising a chassis, a boom mounted on said chassis for vertical movement thereto and projecting forwardly of said chassis, rotary cutter head means including shaft means and drum means mounted on said shaft means for rotation therewith, said drum means comprising a central drum and outer drums adjacent opposite ends of said central drum, supporting arm means including a supporting arm pro- 5 jecting between said central drum and each of said outer drums rotatably supporting said shaft means on said boom to mount said cutter head means to said boom, gathering means below said boom for gathering material mined by said cutter head means, said cutter head means including first sprocket means associated with said central drum adjacent each of its ends and second sprocket means associated with said outer drums at their ends adjacent to said central drum, driving chain means generally centrally of said cutter head means for rotatably driving said cutter head means, said driving chain means including a driving chain drivingly connected to each of said first sprocket means and the thereadjacent said second sprocket means, cutter means carried by said driving chains for mining material during the driven movement of said driving chains, said driving chains including upper and lower runs, and driving means connected to said driving chains for longitudinally driving said driving chains, and the driven movement of said driving chains by their said driving means causing said driving chains to be driven in a direction wherein said lower runs of said driving chains rearwardly convey material towards said gathering means.

2. A mining machine according to claim 1 wherein said cutter head means further comprises extensible end portions in telescoping relationship with said outer drums, said extensible end portions being movable relative to said outer drums for extending and retracting said cutter head means, and means for causing said movement of said extensible end portions. 

1. A mining machine comprising a chassis, a boom mounted on said chassis for vertical movement thereto and projecting forwardly of said chassis, rotary cutter head means including shaft means and drum means mounted on said shaft means for rotation therewith, said drum means comprising a central drum and outer drums adjacent opposite ends of said central drum, supporting arm means including a supporting arm projecting between said central drum and each of said outer drums rotatably supporting said shaft means on said boom to mount said cutter head means to said boom, gathering means below said boom for gathering material mined by said cutter head means, said cutter head means including first sprocket means associated with said central drum adjacent each of its ends and second sprocket means associated with said outer drums at their ends adjacent to said central drum, driving chain means generally centrally of said cutter head means for rotatably driving said cutter head means, said driving chain means including a driving chain drivingly connected to each of said first sprocket means and the thereadjacent said second sprocket means, cutter means carried by said driving chains for mining material during the driven movement of said driving chains, said driving chains including upper and lower runs, and driving means connected to said driving chains for longitudinally driving said driving chains, and the driven movement of said driving chains by their said driving means causing said driving chains to be driven in a direction wherein said lower runs of said driving chains rearwardly convey material towards said gathering means.
 2. A mining machine according to claim 1 wherein said cutter head means further comprises extensible end portions in telescoping relationship with said outer drums, said extensible end portions being movable relative to said outer drums for extending and retracting said cutter head means, and means for causing said movement of said extensible end portions. 